Test tank for marine engines



Dec. 1, 1970 HUNZIKER 3,543,573

TEST TANK FOR MARINE ENGINES Filed Aug. 8, 1968 2 Sheets-Sheet l INVENTOR. LOUIS A. HUNZIKER Af+orney Dec. 1, 1970 L, A, HuNziKER 3,543,573

TEST TANK FOR MARINE ENGINES Filed Aug. 8, 1968 2 Sheets-Sheet 2 57 7| 6 M i 4' w 4-3 3% I I IR l 5 l4 \1 INVENTOR. LOUIS A. HUNZIKER United States Patent 3,543,573 TEST TANK FOR MARINE ENGINES Louis A. Hunziker, 783 Commerce Ave., Lougview, Wash. 98632 Filed Aug. 8, 1968, Ser. No. 751,160 Int. Cl. G01m 15/00, 10/00 US. Cl. 73-1171 9 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION This invention relates to a test tank for marine engines of the outboard type and for inboard engines having a tiltable stern drive unit wherein the testing is conducted while the boat is mounted on a boat trailer.

Test tanks have heretofore been developed for outboard engines removed from the boat and mounted on the tank itself. Test tanks have also been proposed for use with an outboard engine mounted on a boat while the boat is mounted on a trailer. However, in the latter devices the height of the trailer and height of the boat are critical and so the devices are not of general application to trailers and boats of different heights. Also, they are not usable with boats having an inboard engine with a tiltable stern drive unit because the usual stern drive unit cannot be tilted up high enough to clear the edge of the tank by merely backing the trailer toward the tank. The previous devices have therefore been of too limited application to supply the requirements of the present wide variety of boats, engines and trailers.

It is desired to provide a test tank which will accommodate boats of different sizes with stern drive units as well as outboard motors and wherein the height of the trailer is not critical.

SUMMARY OF THE INVENTION In the present construction, the test tank is mounted for rocking movement in a well in the service floor. By rocking the tank, the front end may be depressed to a sufficiently low level to clear the lower end of a stern drive unit when the unit is tilted up even though the boat may be mounted on a relatively low trailer. After the stern drive unit has cleared the end of the tank, the tank may be raised to operative position. The invention also includes additional improvements to facilitate placing the stern drive unit in the tank and to seal the end of the tank against the transom of the boat.

Objects of the invention are, therefore, to provide an improved test tank for marine engines, to provide a test tank which will accommodate stern drive units as well as outboard motors, to provide a test tank having a front end which may be lowered to clear a stern drive unit when a boat is backed up to the test tank, to provide a test tank which is rockable on a pivotal mounting, to provide sealing means to seal the front end of the test tank against the transom of a boat and to provide a test tank which is of general application to a Wide variety of different sizes and types of trailers, boats and engines and which is convenient and easy to use.

The invention will be better understood and the foregoing and other objects and advantages will'become apparent from the following description of the preferred embodiment of the invention disclosed in the accompanying drawings. Various changes may be made in the details of construction and arrangement of parts and certain features may be used without others. All such modifications within the scope of the appended claims are included in the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a test tank, with parts broken away, embodying the principles of the invention;

FIG. 2 is a longitudinal sectional view of the tank;

FIG. 3 is a fragmentary view similar to FIG. 2, showing the baffle deflector in raised position;

FIG. 4 is a front elevation view of the tank;

FIG. 5 is a side elevation view, showing the front end of the tank tilted downward in receiving position; and

FIG. 6 is a view similar to FIG. 5, showing the tank in operative position.

DESCRIPTION OF THE PREFERRED EMBODIMENT The bottom of tank 10 extends into a well 11 in floor 12. An angle iron supporting frame 13 is fitted into the floor opening as shown in FIG. 1. Frame 13 is equipped on its opposite sides with bearings 14 for a pair of tank trunnions 15. These trunnions are mounted on the tank a little behind its center so that the tank will tend to overbalance in a forward direction.

The front end of the tank is supported in adjusted position by a hydraulic jack 20. Jack comprises a vertical hydraulic cylinder 21 mounted on frame 13 by means of a support bracket 22 and pivot pin 23. Piston rod 24 is pivotally connected at 25 with a bracket 26 on the side of the tank. This is a conventional hydraulic jack having a pump handle 27 for pumping hydraulic fluid into the lower end of cylinder 21 for raising the piston rod. The jack also includes a relief valve (not shown) to relieve hydraulic fluid from the lower end of cylinder 21 for lowering piston rod 24 by gravity under the weight of the front end of the tank.

The tank is shown raised to operating position in FIGS. 1 and 6 wherein it is approximately horizontal and in lowered, receiving position in FIG. 5. The lower limit of the rocking movement on trunnions 15 is established by engagement of stop 30 with a resilient abutment 31 mounted on frame 13.

The rear end of the tank is closed by a housing 32 having an exhaust vent 33. Side Walls 34 extend from housing 32 to a flat front wall 35. The central portion of front wall 35 is cut down at 36 to provide easy access to a top opening 40.

Front wall 35 is equipped with an arcuate resilient seal 41 extending under and around the ends of the cut down edge 36 to engage the transom of the boat. This seal may comprise a segment of a rubber inner tube from an automobile tire having a valve 42 for inflation. The cut ends of tube 41 are sealed and secured to opposite side walls 34 by a pair of clamp plates 43. Mid portions of tube 41 are secured to front wall 35 by lacing 44 or other suitable means.

A pair of horizontal side plates 45 extend inward from opposite side walls 34 to restrict the opening 40 to the width of the top edge 36. During operation, the forward portion of opening 40 is closed by a baffle deflector with vertical side wings 51 which have a sliding fit with the inner edges of plates 45. Batfle deflector 50 is pivotally mounted at its rear end on pivots 52 for raising and lowering by handle 53.

Handle 53 is mounted on a link 54 which is pivotally connected at 55 with the front end of the bafl le deflector. A short distance from its rear end, the link 54 is pivotally connected at 56 with a second link 57. Link 57 is pivotally 3 connected at 58 with housing 32. By lifting handle 53, the baffle deflector 50 is raised to open position as shown in FIG. 3 and by pressing down on the handle 53, the baffle deflector is lowered to closed position as shown in FIGS. 1 and 2. In closed position, a stop 59 on the rear end of link 54 engages the link 57 to lock the joint in over-center position so that the baflle deflector cannot be forced upward by the pressure of water on its under side.

FIG. shows a boat 60 on a trailer 61 backed up to the front end of the test tank, the latter being in lowered position. The boat has an inboard engine (not shown) and a conventional stern drive unit 62 pivotally mounted at 63 on the transom 64. Drive unit 62 transmits power from the engine to propellor 65.

The pivotal mounting 63 ordinarily does not permit drive unit 62 to raise high enough to clear the front edge of a stationary test tank which is itself high enough to submerge the propellor when the unit 62 is returned to -vertical operating position as shown in FIG. 6. By depressing the front end of the tank as shown in FIG. 5, the lower end of unit 62 will pass over the cut-down edge 36 of front wall 35 placing the unit 62 and propellor 65 above the top opening 40.

Then the unit 62 is lowered to vertical position and the front end of the tank is raised by jack 20 as shown in FIG. 6. Water may be added to the tank if necessary to submerge the propellor to the proper depth. Finally, baffle deflector 50 is lowered to operating position and a pair of ropes 70 are connected to the boat, causing the transom to engage and compress the seal 41.

There is one rope 70 on each side of the tank, each rope being connected at 71 with housing 32 and connected with an eye 72 on the transom. Each rope is equipped with a conventional lever action tightening device 73 which not only holds the transom in tight engagement with seal 41 but also permits the propeller thrust from pushing the boat forward away from the tank. The arcuate shape of seal 41 will retain a water level as high as side walls 34.

FIG. 2 shows the operative position of propellor 65 in the tank. The water discharged rearwardly from the propellor is directed in a return circuit by a plurality of baflles 75, 76 and 77 as indicated by the arrows. Curved baflles 77 at the front end of the tank direct the returning water substantially horizontally into the propellor to simulate the condition of a boat traveling through water and prevent cavitation. This permits the engine and the whole propulsion system to be tested under load and under normal operating conditions the same as if the boat were afloat.

A single operator can perform the test or demonstrate the operation at any time of the day or night and in any season of the year without the necessity of hauling the boat to a body of water, launching it and taking along another person to drive the boat. A mechanic making adjustments on the engine cannot drive the boat at the same time. Certain engine adjustments and turning can be accomplished best under load. The present test tank allows normal operation of the cooling system and all other functioning parts so that a tank test is equivalent to a run afloat.

Although a stern drive with an inboard engine is illustrated and described by way of example, the present test tank has the same advantages with an outboard type of motor. The outboard motor tilts up substantially the same as shown in FIG. 5 and the propellor drive housing is disposed vertically in operation the same as shown in FIG. 6. The present arrangement eliminates the work of removing the motor from the boat and disconnecting the throttle and steering controls and permits the testing, adjusting or demonstrating of these controls.

Baflle deflector 50 extends forward substantially to the propellor and permits the engine to be operated at substantially full power. Seal 41 prevents loss of water from the tank and permits the water level at front wall 35 to rise above the edge 36. These features also permit sulficient depth of water to insure full loading of the propellor under all conditions.

Jack 20 provides vertical adjustment to accommodate drive units 62 of different height, to accommodate large and small boats where the transom is of varying height and where the pivotal connection 63 is at varying heights above the bottom of the boat and it also accommodates trailers of different heights. The tank does not have to be precisely horizontal in operating position but is adjusted to fit the boat. This makes the test tank of universal application to substantially all boats having an outboard motor or an inboard motor with stem drive.

Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

1. A test tank for marine engines comprising a tank having a front end adapted to receive a stern drive unit on a boat when the boat is backed up to the tank, a transverse pivotal support for said tank, and means for rotating said tank on said pivotal support to lower said front end so that said drive unit will pass over said front end and to raise said front end to adjusted position relative to said drive unit.

2. A test tank as defined in claim 1, said rotating means comprising a jack. 7

3. A test tank as defined in claim 1, said tank being mounted in a well in a floor.

4. A test tank as defined in claim 1, said front end of the tank being cut down below the top of the side walls of the tank, and a seal on said front end for engagement with the transom of the boat.

5. A test tank as defined in claim 4, said seal comprising an arcuate inflatable rubber tube.

6. A test tank as defined in claim 4 including means to pull said transom against said seal.

7. A test tank as defined in claim 6, said pulling means comprising ropes connected between said tank and said transom.

8. A test tank as defined in claim 2 including a supporting frame having bearings, said pivotal support compris ing trunnions on said tank mounting in said bearings, said jack being connected between said frame and said tank.

9. A test tank for marine engines comprising a tank having a front end lower than its side walls, a horizontal 'frame surrounding said tank, a pair of trunnions on opposite sides of said tank, bearings on said frame supporting said trunnions, a jack on said frame connected with said tank for rotating said tank on said trunnions, a seal on said front end arranged to engage the transom of a boat backed up to said tank, and means on said tank for pulling said transom against said seal.

References Cited FOREIGN PATENTS 45,235 10/1961 Poland.

RICHARD C. QUEISSER, Primary Examiner M. SMOLLAR, Assistant Examiner US. Cl. X.R. 

